Day 557 March 10, 1941

At midnight 460 miles Southeast of Iceland, U-552 sinks Icelandic trawler Reykjaborg with the deck gun and anti-aircraft gun (12 killed). 3 survivors escape on a raft (1 dies, 2 picked up by British corvette HMS Pimpernel on March 14).

British submarine HMS H.28 is damaged in a collision with a freighter in the Irish Sea (under repair at Belfast until April 14).

Operation Canvas. General Platt's Nigerian Brigade has advance 450 miles North from Mogadishu, Italian Somaliland, into Ethiopia. They meet Italian resistance at Degehabur, on the road 100 miles South of Jijiga. Known as the "Hindenburg Wall", these old trenches and gun pits were built by the Ethiopians in 1936 against the Italian invasion during the 2nd Italo-Abyssinian War.

Continuing the attack on Italian convoy from Palermo, British submarine HMS Unique sinks SS Fenicia 100 miles Northwest of Tripoli, Libya.

Overnight, Luftwaffe bombs town of Portsmouth and Royal Navy docks, damaging destroyers HMS Sherwood, HMS Witherington (under repair at Portsmouth for 5 months) & HMS Tynedale (repaired in 9 days), training ship HMS Marshal Soult (ex-monitor with 15-inch guns removed) and 4 minesweeping trawlers. Minesweeping trawler HMT Revello is sunk (1 killed, Revello will be raised, repaired and recommissioned). 10 shore-based Naval personnel are also killed.